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Flows of DOC from Territory of Latvia and Factors Controlling it

Maris Klavins1
1 Department of Environmental Science, University of Latvia

P 7.13 in Controls of dissolved organic matter fluxes in ecosystems

Poster Session 1 on Monday, 16:30-18:30

Global environmental change very much influence flows of substances. Of importance in this respect are flows of natural organic substances – humic substances (major part of dissolved organic carbon DOC). Transfer from adjacent areas, but also industrial effluents and non-point pollution sources can be sources of increased fluxes of DOC. Flows of DOC has been analyzed worldwide, but there are few publications concerning water chemical composition and DOC in waters of Latvia. The aim of this study is to describe long term changes of DOC concentrations in surface waters quality of Latvia, factors controlling DOC runoff, spatial variability of water chemical composition, possible impacts of pollution sources, and the measures to protect national water resources.

Within this study, the DOC concentrations, particulate organic substances as well as spectral characteristics (UV spectra, 3D fluorescence spectra) in the major rivers and lakes of Latvia have been determined. Impact of other major water ingredients on DOC budgets has been studied. The dynamics of DOC flows depending on land-use pattern and soil properties in Latvia are described, including emissions by industrial and agricultural production. These changes are especially dramatic during the transition period. The water chemistry of a large number of lakes and rivers has been determined and the possible impact of water chemical composition on water quality has been evaluated.

Regarding the high concentrations of dissolved organic substances in surface waters and in sediments, their binding capacities of DOC with metal ions were evaluated. The dominating pathways for metals are considered stressing the impact of land-use on metal accumulation. The impact of water chemistry, land-use and other natural conditions on metal accumulation and fluxes are discussed. Water biological quality in Latvia has been evaluated. Recommendations for environmental policy in Latvia and prevention of surface water pollution are presented.

Letzte Änderung 19.06.2014